JP2697042B2 - Printer hammer drive for printer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of urging a printing hammer with a novel configuration in urging a printing hammer of a printing press.

[Conventional technology]

An embodiment of the prior art printing hammer urging method will be described with reference to FIGS. 4, 5, and 6. FIG.

In FIG. 4, reference numeral 1 denotes an input terminal of an unstable power supply voltage, and 2 denotes a power supply for stabilizing the voltage. 3 the control unit, Co is a coil and a capacitor capacitor, L and Cr is smoothing the output cooperates with Daiodo PD ₁ the intermittent current in the control unit 3 for smoothing the non-stable power supply voltage. 4 is a line for feeding back a regulated voltage generated in the capacitor C ₁ to the control unit 3. 5 represents a stabilized power supply terminal or voltage. Reference numerals 6 and 7 denote driving units of the printing hammer according to the present invention, and reference numeral 7 denotes one driving unit when a plurality of printing hammers are used. _{CL 1, CL 2, ......,} CLn is a coil for urging the hammer. _{ZD 1, ZD 2, ......,} ZDn is provided in order to consume the coil CL _1, ..., the electromagnetic energy accumulated in at Zenadaiodo. Tr ₁ is a switching transistor for connecting the power supply 2 to the coils CL _1, ..., And n−1 identical transistors are disposed in a portion named 11 drive circuits. Reference numeral 8 denotes a shift register for sequentially shifting and storing n pieces of print data by a shift clock. Reference numeral 9 denotes a latch circuit for simultaneously shifting and storing print data of the shift register 8 by a latch pulse. Reference numeral 10 denotes an enable signal which is controlled by an enable signal which provides print data to the transistors of the drive circuit 11 with n outputs of the latch circuit 9 at a predetermined time width.

The above is an example of the configuration of the prior art printing hammer biasing method according to the present invention.

The flow of energy consumption from the power supply 2 by taking out the driving unit 7 for urging the hammer will be described.

FIG. 5 is an equivalent circuit of the drive unit 7 when the voltage of the power supply 2 is 30 V. Figure 5 (a) is a system equivalent circuit of the transistor Tr ₁ is conductive, FIG. 5 (b) is an equivalent circuit after the transistor Tr ₁ is turned into a non-conducting state.

The value of the electromagnetic coil CL ₁ changes during operation, but for simplicity, it is assumed to be constant 3 mH and an equivalent constant of 20 Ω.

Equivalent constants of the transistor Tr ₁ is only resistance 0.5Ω omitted it is saturated voltage term.

The current i ₁ in FIG. 5 (a) can be expressed as follows.

i ₁ = 1.463 (1−exp (−t / τ ₀ )), τ ₀ = 3 × 10 ⁻³
/(20+0.5)=1.463×10 ^-4 s, t = time here, the conduction width of the transistor Tr ₁ as 200 [mu] s,
Calculate the energy relationship of the system.

The energy P _IN1 supplied by the power supply is Energy consumption P _R1 of resistance 20.5Ω is, The energy P _CL stored in coil CL ₁ is It is. Naturally, the above relationship is P _IN1 = 3.99 mJ = P _R1 + R _CL = 2.21 m J + 1.78 mJ = 3.99 mJ.

Then calculates the relationship of FIG. 5 equivalent circuit after the transistor Tr ₁ is cut off (b). The equivalent constant of the Zena diode
Replace with 75V power supply voltage and 0.5Ω resistor.

At t = 0, i ₂₀ = i ₁ (200 μs) = 1.09 A, t = ∞, i ₂
When i ₂ is obtained under the condition that ∞ = (30−75 V) /20.5Ω=−2.2 A, i ₂ = 3.29exp (−t / τ ₀ ) −2.2. From this, when the time τ at which i ₂ = 0 is obtained,
τ = 5.88 × 10 ⁻⁵ s.

 FIG. 6 shows the current obtained in FIG.

The fact that the maximum return cycle is 500 μs in FIG. 6 indicates that the normal print hammer operation cycle is before and after this. In addition, when printing characters and figures directly on recording paper with a print hammer, recording paper, ink ribbon, and print ring to express characters or figures with a print hammer, characters and figures are printed in a dot matrix with the shape of the print hammer as dots. There are various schemes for representing graphics, but the present invention is applicable to any scheme.

 Now, the energy relationship from 0 to τ is calculated.

Energy P _IN2 supplied by power supply 2 is Energy P _R2 that all resistance 20.5Ω has been consumed, Energy consumed by Zena Diode's equivalent power source P _ZDU
Is Becomes

Therefore, the total energy consumption of Zena Diode ZD P _ZD = P
Energy consumed by _ZDU + _0.5Ω resistor = 2.25 + 0.43 • 0.0.
5 / 20.5 = 2.26 mJ.

In FIG. 5, the energy P _IN supplied by the power supply 2 is P _IN = P
_{IN1 + P IN2 = 3.99 + 0.9} = 4.89mJ and therefore made, Zenadaiodo energy consumption ZD 46% of energy supply of the power supply 2
Also reach. Zenadaiodo ZD is necessary in order to disappear quickly the current i ₂ in order to operate the hammer at a high speed. The higher the equivalent power supply voltage, the more the current i ₂ disappears.

Further, when actually applied, assuming that the number of printing hammers is 24 and the return frequency is 2 KHz, the power P supplied from the power supply 2 is P = 4.89 × 10 ⁻³ × 24 × 2.
× 10 ³ ≒ 235 W, power consumption P _{ZD of} Zena Diode is P _ZD =
2.26 × 10 ^-3 × 24 × 2 × 10 ³ ≒ 108W.

The above is the state of the printing hammer urging method according to the prior art.

[Problems to be solved by the invention]

However, in the above-described conventional technology, there is a large waste of energy consumption of the zena diode as much as 46% in terminating the urging of the hammer within a predetermined time. The zena voltage of zena diode was fixed at 75V in the above, but it is actually 75V
There is a large variation of ± 7 V, and there is also a large problem that the variation of the disappearance time of the current i ₂ described above occurs and the hammer operation cycle becomes unstable.

Therefore, the present invention is to solve such a problem of the prior art.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing hammer urging method for recovering energy stored in a coil of a printing hammer, reducing unnecessary power consumption, and stably urging the printing hammer.

[Means for solving the problem]

A printing hammer driving device for a printer according to the present invention is a printing hammer driving device for a printer, which energizes an electromagnetic coil and urges the printing hammer by an electromagnetic force generated to perform recording. Switching means, energy storage means for storing the electromagnetic energy stored in the electromagnetic coil via a one-way element, voltage detection means for detecting the voltage of the energy storage means, and between the energy storage means and a power supply Second switching means for controlling conduction of the energy storage means while the voltage detection means detects that the voltage is equal to or higher than a predetermined voltage. The stored energy is fed back to the power supply.

[Action]

By storing the electromagnetic energy of the electromagnetic coil in the energy storage means, unnecessary power consumption such as zena diode does not occur. Since the voltage of the energy storage means is controlled to be substantially constant by the detection means and the second switch means, the energization of the hammer is also controlled to be constant.

〔Example〕

FIG. 1 is a diagram showing a specific configuration of an embodiment of the present invention, and FIGS. 2 and 3 are diagrams for explaining the specific configuration of FIG. In FIG. 1, the same numbers or numbers as those in FIG. 4 have the same meanings or means.

Diodes the electromagnetic energy of the electromagnetic coils CL ₁ , CL ₂ , ...
Collected via D ₁ , D ₂ ,... And accumulated in the capacitor C ₂ . As a result, each time the hammer is energized, the capacitor
Voltage of C ₂ is increased.

The voltage of this capacitor C ₂ is
This is equivalent to the ZD voltage of ZD.

Therefore, it is necessary to substantially constant voltage of the capacitor C _2. Therefore, the detection means 13 determines whether the value is equal to or more than a predetermined value. The determination signal of the detection means 13 is modulated by the gate 14 into an intermittent signal. The reason why the signal is modulated into an intermittent signal is that when a feedback loop has a coil, the feedback efficiency is increased. Although FIG. 1 shows an enable signal and a shift clock as modulation signals, other clocks may be used.

The passed judgment signal is given to the control electrode of the transistor Trs. Transistor Trs is excess energy of the capacitor C ₂ to the point A of the power supply 2 via a feedback line 13 conducts is migrated. Eventually the voltage of the capacitor C ₁ is converted as electromagnetic energy in the coil L increases. The control unit 3 detects the voltage rise by the detection line 4 and cuts off the power from the input terminal 1.

As a result, external power supply is saved.

The feedback point of the feedback line 13 may be the input terminal 1 or the output terminal 5 (not shown), but the energy feedback efficiency is low. In these cases, although not shown, the same effect can be obtained by inserting another coil into the feedback line 13.

The still, it is desirable voltage of the capacitor C ₂ is substantially constant, or hammer hammer actuating descends during non-operation is fed in a separate power supply so as to not inaccurate, electromagnetic extent that the hammer will not operate A method for exciting the coils CL ₁ , CL ₂ ,... Is not shown, but may be used. If not in this way, during a long time when printing after Kyushirushi the voltage of the capacitor C ₂ rises to a predetermined value is what unsightly printing results.

Now, one driving unit 7 is taken out in FIG. 1 and the energy transfer relationship will be described with specific numerical values. Although FIG. 2 shows an equivalent circuit in each state, the conduction state of the transistor Tr ₁ is omitted are the same as Figure 4.

Figure 2 (a) is an equivalent circuit after the transistor Tr ₁ is blocked, FIG. 2 (b) is an equivalent includes a smoothing coil and a capacitor C ₁ of the power supply 2 when the transistor Trs becomes conductive circuit, Figure 2 ( (c) is a diagram showing an equivalent circuit after the transistor Trs is cut off.

The condition of FIG. 2 (a) is that at T = 0, i ₂₀ = 1.094, the voltage V _C2 of the capacitor C ₂ = 75V, t = ∞, i∞ = 0, V _C2 ∞ = 30V
It is. When the current i ₂ is obtained from these, i ₂ = 3.33exp
(−6.78 × 10 ³ t) −2.24exp (−4.91 × 10t).

Here, when the time τ at which i ₂ = 0 is obtained, τ = 5.9 × 10 ⁻⁵ s. Find the energy relationship between 0 and τ.

Energy P _IN2 supplied by power supply 2 is Energy P _R2 resistance 20.5Ω has been consumed, The increased charge of capacitor C ₂ is Since the number of clones increases, the voltage rise is 2.99 × 10 ^-2 V.
Therefore, the energy increase [Delta] P _C2 of the capacitor C _{2 is, ΔP C2 = 1/2 ×} 10 -3 F · (75.0299 2 -75 2) = 2.24mJ R IN2 + 1 / 2Li 20 2 = 0.9 + 1.78 = 2.68mJ ≒ P _R2 + ΔP _C2 =
0.43 + 2.24 = 2.67 mJ.

2.24mJ / 2.68mJ = 83.5% is the energy moves to the capacitor C _2.

The case of feeding back the increased energy of the capacitor C ₂ to the power 2 is described in the second view (b).

For simplicity, it is assumed that there is no current from the control unit 3. The equivalent constant of the transistor Trs is set to 0.5Ω. C ₁ = 50
The current i ₃ and the voltage V _C2 of the capacitor C ₂ are obtained by setting the value of the coil L to 0.1 μH and 0.5 Ω at 00 μF.

The conditions are t = 0, i ₃ = 0, charge QC ₁₀ = 30 ^V × 5 × 10 ^-3 = 0.1
5 clones (charge of the capacitor _{C 1), qc 20 = 75.0299} ×
When the differential equation is solved from the 10 ⁻³ clone t = ∞ and i ₃ = 0, qc ₁₀₀ = 0.18752491 clone qc ₂ ∞ = 3.750498 × 10 ⁻² clone, i ₃ = 62.4 (exp (−8.61 × 10 ³ t) −exp (−1.39 × 10
³ t)) V _C2 = −7.25exp (−8.61 × 10 ³ t) + 44.8exp (−1.39 × 1
0 ³ t) +37.5 V When _C2 changes from 75.0299 V to 75 V, the detection means 13 turns off the transistor Trs. When this time τ is obtained, τ = 1.0
7 × 10 ^-5 s. The current i ₃ τ at this time is i ₃ τ = 4.57 A.

The energy Pr ₁ consumed by the resistor 0.5 + 0.5 is Electromagnetic energy 1 / 2Li ₃ ² τ = 1.05 mJ The energy ΔPc ₁₁ increased by the capacitor C ₁ is ΔPc ₁ = 0.90 mJ or more, and 2.24 mJ released by the capacitor C ₂ is Pr ₁ + 1 / 2Li ₃ ² τ + ΔPc ₁ = 0.08 + 1 .05 + 0.9 = 2.03mJ. Here, a calculation error of 0.21 mJ has occurred, which is also regarded as resistance consumption.

Next, the state after the transistor Trs is cut off is shown in FIG.
Will be described.

Under the condition, t = 0, i ₄₀ = i3τ = 4.57A, t = ∞, i ₄ ∞ = 0, etc., and solving the differential equation, i ₄ = 35.95exp (−9.8 × 10 ³ t) − 31.38exp (−2.04 × 1
0 ² t) When the time τ at which i ₄ = 0 is obtained, τ = 1.42 × 10 ⁻⁵ s From these, the energy increase ΔPc of the capacitor C ₁ is obtained.
₁₂ = 0.95 mJ. The electromagnetic energy of Fig. 2 (b) 1.05
mJ becomes ΔPc ₁₂ = 0.95 mJ and the resistance consumption is 0.1 mJ.

The current waveform of the transistor Tr ₁ described in Figure 2 is shown together with the current waveform while conducting is the third diagram. i ₃ and i ₄ are are changing the current unit.

Summarizing the above, the energy supplied by power supply 2 P _IN1 + P _IN2 = 3.99 + 0.9
= 4.89 mJ, and the energy ΔPc ₁₁ + ΔPc ₁₂ = 0.9 + 0.95 = 1.85 mJ returned to the capacitor C ₁ of the power supply 2. The recovery rate is 1.85 / 4.89 = 37.8%. 62.2% of the system's resistance consumption will be given mostly to the hammer.

〔The invention's effect〕

As described above, according to the present invention, the energy stored in the electromagnetic coil is temporarily stored in the storage means, and this storage means is operated like a conventional Zena diode without consuming power. Therefore, the operating characteristics of the printing hammer are not affected at all.

The surplus energy stored in the storage means can be efficiently returned to the power supply unit.

In addition, it is extremely effective to reduce the power of the printing machine and the above characteristics without increasing the cost by replacing the zener diode with inexpensive diodes, capacitors, and transistors.

[Brief description of the drawings]

FIG. 1 is a diagram showing a specific configuration example of an embodiment of the present invention. 2 (a) to 2 (c) are diagrams showing equivalent circuits and equivalent constants for explaining the operation process of FIG. FIG. 3 is a diagram showing a current waveform in the operation process of the present invention. FIG. 4 is a diagram showing a configuration example of an embodiment according to the prior art according to the present invention. 5 (a) and 5 (b) are diagrams showing an equivalent circuit and an equivalent constant in the operation process of FIG. FIG. 6 is a diagram showing a current waveform in the operation process of FIG.

Claims (1)

(57) [Claims] 1. A printing hammer driving device for a printer, which energizes an electromagnetic coil and urges a printing hammer by an electromagnetic force generated to perform recording, wherein: a first switching means for controlling energization of the electromagnetic coil; Energy storage means for storing electromagnetic energy stored in the electromagnetic coil via a one-way element, voltage detection means for detecting a voltage of the energy storage means, and a second control means for controlling conduction between the energy storage means and a power supply. 2
Switching means, wherein the second switching means is turned on while the voltage detection means detects that the voltage is equal to or higher than a predetermined voltage, and the stored energy of the energy storage means is fed back to a power supply. A printing hammer driving device for a printer, wherein the driving hammer driving device is configured to perform the following.